Gas permeation and separation by an asymmetric polyimide hollow fiber membrane

Abstract The permeation of various gases was measured through an asymmetric polyimide hollow-fiber membrane. Whereas the permeability of pure gases slightly decreased with increasing pressure difference, the membrane had high enough selectivity to separate mixtures of small and large molecules. The permeation of mixtures of CO 2 -CH 4 and O 2 -N 2 appeared to follow the constant-permeability model which took no account of dependence of partial pressure on permeability. In H 2 -CO mixtures, the permeability of H 2 was depressed considerably due to the presence of CO, and model prediction on the basis of the dual-mode transport model showed fairly good agreement with the data obtained.